90 brakes on 91gsx?

[dspecv]

I have a 91 GSX, and had to replace the rotor yesterday. When I tried putting a 91 rotor on there, it was quite a bit larger than the one originally on there, and the caliper would not fit over it completely. I ended up having to use a rotor from a 90 gsx, which is the same as the one originally on the car. My car shows a build date of March 1991, so would the early build be the reason for smaller rotors/calipers? That just seems strange to me. Just looking for some clarification on this.

 

[motomattxxx]

I have a 91 GSX, and had to replace the rotor yesterday. When I tried putting a 91 rotor on there, it was quite a bit larger than the one originally on there, and the caliper would not fit over it completely. I ended up having to use a rotor from a 90 gsx, which is the same as the one originally on the car. My car shows a build date of March 1991, so would the early build be the reason for smaller rotors/calipers? That just seems strange to me. Just looking for some clarification on this.

Yes, that is why they ask you the build date when you buy front brake parts.

 

[Cs4g63]

As long as you are talking about the front rotors the AWD takes the same rotors from 4/89-5/92. After that the front changes to the larger rotors with the dual piston caliper setup. On the FWD cars the front rotors and pads stay the same for 90-99.

So I am thinking that someone just gave you the wrong rotor when you went to get it.